Lunch box



Feb. 12, 1952 E; H, GRONLUND 2,585,310

LUNCH BOX Filed NOV. 4, 1949 2 SHEETS--SHEET l E. H. GRONLUND Feb. 12, 1952 LUNCH BOX 2 SHEETS--SHEET 2 Filed Nov. 4, 1949 Z oooooooomm Selph- JNVENTOR.

' ERNST H, Gao/w. wvo.

BY WM ATTORNEY.

Patented Feb. 12, 1952 LUNCH Box Ernst H. Gronlund, Algonac, Mich., assgnor to Electrolunch Co., Algonac,'Mich., a copartner- Application November 4, 1349. Serial No. 125,536

(ci. 21a- 19) My invention relates to a new anduseful `1 Ir 1.

proveme'nt in an electrically heated lunchbox and has for its object the provision of a lunch boX so arranged and constructed that the contents thereof may be heated to any desired temperature within proper limits.

Another object of the invention is the provision of a lunch box so constructed and arranged that a heating unit and a compartment container may be easily and quickly mounted in the lunch box.

Another object of the invention is the provision in an electrically heated lunch box of means whereby the temperature may be adjusted to various degrees.

Another object of the invention is the provision in a lunch box of this class of a compartment forming container so arranged and constructed Athat articles may be placed therein. and retained in separated relation for facilitating the transference of. heat.

AAnother' object of the invention is the provision of an electrically heated lunch box so constructed and arranged that it will be simple in structure, economical of manufacture, durable, compact and highly eiicient to use.

Other objects will appear hereinafter.

It is recognized that various modifications and changes may be made in the detail of structure illustrated and it is understood that the form illustrated is but the preferred embodiment.

Forming a part of this specication are drawings in which,

Fig. 1 is a side elevational view of the invention with parts broken away and parts shown in section,

Fig. 2 is an end elevational view of the invention with parts broken away,

Fig. 3 is a top plan view of the invention in Open form,

Fig. 4`is a reduced view taken on line 4-4 of Fis# 1,

lFig'. 5 is a fragmentary sectional viewv taken online 5-5 of Fig. 4. Y

Fig. 6 is a fragmentary sectional view taken on line 6-6 of Figl 1,

Fig. 'I is a fragmentary sectional view showing lthe thermostat used in the invention.

As shown in the drawings, the lunch box comprises a lower section 9 and an upper section IB hingedly connected together and secured in closed position by the clasp II andfhaving a handle I2 Ill.,l and projecting outwardly from which are'the resilient extension bars or tongues |5.

A heater housing I'I is provided with the flared edges I 8 which are adapted to seat against a container 2U, having an outwardly projecting flange 2I at its upper edge provided with a downwardly projecting flange 22. Mounted in the section 9 is a transverse partition 23 to which the flange 22 is fastened Aby means of the rivet or screw 24. This flange 22 is also fastened to the walls of the lower section 9 by means of the screws or rivets 26, this being shown in Fig. 1 as being thus secured to the end wall 25 of the lower section 9.

The heater housing I'I is provided at its edges with the inwardly pressed grooves 2.1 to nest with the inwardly pressed grooves 28 formed in the walls of the container 2U so that there are thus provided, on the interior of the container 20 the separating or circulating beads or ribs 29 and `30, the ribs 29 being formed in the bottom I5 and the ribs in the side walls. In these beads or ribs 29 are formed openings 3 I.

Mounted in the housing I'I is a heating element 32 secured therein by means of the retaining blocks 33 formed from insulating material. One end of the heating element 32 is connected to the terminal 34 to which is also connected one end of the wire 36. The opposite end of the heating element 32 is connected to the terminal 35. This terminal 35 is connected to the end of the metallic prong 39 which is mounted in the block 4I. This prong 39 is in spaced relation to the prong 4U which connects to the terminal 31 to which one end of the wire 38 is attached. There is thus provided a plug-in socket, the block 4I being projected into the opening 42 formed in the end wall 25.

Mounted on the container 20 is a bracket 43 on which is mounted a resilient metallic plate. 44 insulated from the bracket 43 by means of a layer 45 o :i insulating material. This contact pla-te 44 is insulated by the layei1 46 of insulating material from the contact plate 4l' which is bi-metallic and which also is insulated by the layer of insulation 48 from the metallic plate 49 through which are extended the rivets 5U. Mounted on the contact plate 44 is the contact 5I and mounted on the plate 4T is the contact 52, these contacts being adapted to engage. A wire 36 is connected to the plate 44 and the wire 31 is connected with -the plate '41.' The construction is such. that when the temperature of the interior onf-the lunch box reaches" a predetermined degreen, the plate 41 willy curl'so as'to'withdraw the contact 52 from engagement with the contact 5I,

thus breaking the circuit to the heating element 32. Mounted in the flange 2l is a nut 53 of insulating material through which is threaded the adjusting screw 54 which bears against the insulating plate 45. The construction is such that by turning the screw 54 downwardly as shown in Fig. '7 the plate 44 will be flexed downwardly so that a higher degree of temperature would be required in order to have the contacts 5l and disengage. Similarly by unthreading the screw and allowing the plate 44 to spring upwardly, a situation would be developed where the contacts 5I and 52 would separate at a lower temperature.

As shown in Fig. 3, the ribs 29 and 30 serve to separate the compartments 55, 56 and 51 and the partition 23 forms, with the end wall of the lower section 9, a compartment 58 in which various articles may be deposited. As shown in Fig. l, receptacles 59, 60 and 6| may be mounted in the housing 20 between the ribs and the end wall and these receptacles are held in position through their engagement with either the members i3 or i5. Likewise, articles may be deposited in the compartment 58 which would be held in position by means of the paneled cross bar It or the tongue l5.

In use the user would place in the compartment 5B such articles as sandwiches, bread, cake, etc., and in the receptacles 59, 60 and 6| would be placed those articles of food which it is desired to consume while hot. Shor ly before using the food contained in the lunch box, the user would plug into the socket plug so that the heating element 32 would be energized. The heat generated in the housing l I would pass upwardly.. 5

through the channels 30 on the outside of the housing 20 and also along the bottom through the channels formed by the beads 25 and pass outwardly through the openings 3l into the interior of the housing 20. The formation is such that a ready circulation of the heated air would be eiected and a rapid heating of the contents of the lunch box accomplished. By setting the screw 54 at the desired position, the circuit would be broken when the desired temperature of the food contained within the lunch box had been reached.

By removing the screws 24 and 26, the housing 20 and l1 may be easily and quickly removed from the lower section 9 so that the lunch box may be used without the heating element when desired and the heating element thus is rendered accessible for repair and similar operations. The housing il and container 20 are, as already shown, constructed as a unit. After the fabrication of this unit, the same is inserted in the lunch box proper. In the form shown, there is sufiicient clearance between the partition 23 and the end of this unit, to permit the insertion o the unit into .place and its removal therefrom. It is believed obvious that the partition 23 may be removed, if-desired, as the fastening of this unit on three sides to the lunch box will suice to hold the unit rigid. Consequently, the lunch box need not be specically built as the unit may housing; a heating element mounted in said housing, vsaid housing being open at its upper end; a container open at its upper end and seated at its lower end in the open end of said housing housing and secured thereto; a lower section of a lunch box; a partition in said lunch box; a ange on said container; and securing means for securing said flange to said partition and to said lunch box section; a wall on said lunch box section having an opening formed therethrough; an electrical terminal connected to said electric heating element and accessible through said opening.

3. In an electrically heated lunch box; a lower section of the lunch box open at its top; a composite unit positioned in said section and comprising a heater housing and a container, said heater housing being open at its top and said container nesting at its bottom in the top of said housing; a wall on said lunch box section having an opening formed therein; an electric heating element in said housing; terminals on said heating element accessible through the opening in said wall, said housing and said container being secured together in said nesting relation; and spacing ribs projecting inwardly from the inner face of said container intermediate its ends for spacing apart articles positioned in said container.

4. In an electrically heated lunch box; a lower section of the lunch box open at its top; a composite unit positioned in said section and comprising a heater housing and a. container, said heater housing being open at its top and said container nesting at its bottom in the top of said housing; a wall on said lunch box section having an opening formed therein; an electric heating element in said housing; terminals on said heating element accessible through the opening in said wall, said housing and said container being secured together in said nesting relation; and spacing ribs projecting inwardly from the inner face of Said container intermediate its ends for spacing apart articles positioned in said container; an electric circuit to said heating element; a thermostatically controlled switch in said circuit mounted on said container.

5. In an electrically heated lunch box; a lower section of the lunch box open at its top; a composite unit rpositioned in said section and comprising a heater housing and a container, said heater housing being open at its top and said container nesting at its bottom in the top of said housing; a wall on said lunch box section having an opening formed therein; an electric heat- -ing elementin said housing; terminals on said heating element accessible through the opening in said'wall, said housing and said container being secured together in said nesting relation; and

7. In an electrically heated lunch box a heaterr housing; a heating element mounted in said* housing, said housing being open at its upper:

end; a container positioned above said heater yhousing and composite therewith; a lower section of a lunch box; a partition in said lunch box;v a flange on said container; securing means for securing said flange to said partition; and a wall on said lunch box section having an opening ll 24871196 6 therethrough and an electrical terminal connected to said electric heating element and accessible through said opening.

ERNST H. GRONLUND.

REFERENCES CITED The following' references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Y Date 1,054,318 Schwartz Febr 25, 1913 1,979,222 Goodwin Oct. 30, 1934 2,146,608 Welle Feb. '7, 1939 Douglass Jan. 16, 1940 

